DESCRIPTION (Applicant's Description) This Second International Conference on the mutagenic and carcinogenic risk from environmental and endogenous chemicals will bring together 40-50 scientists from the U.S. and Europe to discuss the detection and chemical and biological effects of cyclic DNA adducts formed by such chemicals. This specific aim should lead to a better understanding of how to reduce these health hazards known, through epidemiology, to result in specific human cancers. The Conference will focus on adducts such as malondialdehyde, an oxidation product of fat; benzene which is present in gasoline, cigarette smoke, etc.; vinyl halides which are used to a very large extent in industry; acrolein which is found in tobacco smoke; mucochloric acid and MX, both highly mutagenic and carcinogenic, from chlorination of drinking water; halogenated hydrocarbons, chemotherapeutic agents such as BCNU, CNU and other halo-nitrosoureas, and products of reactions of other environmental chemicals. The sessions will cover (1) Occurrence and methods of detection; (2) Chemistry; (3) Formation of cyclic adducts from exogenous and endogenous sources; (4) DNA repair and effects on replication; (5) Mutagenesis and carcinogenesis; (6) Use of cyclic adducts as biomarkers. The Proceedings of the Conference will be published by the International Agency for Research in Cancer (IARC) and widely distributed so that many more scientists than present at the meeting and libraries will have this as a reference book.